Insects are the most numerous of all living organisms and nearly one million species constitute approximately 70 percent of all animal species. Of these, about 1 percent are considered significant pests. Overall, insects are known to attack humans and domestic animals; transmit human, animal, and plant diseases; destroy structures; and compete for available supplies of foods and fibers.
Of the insect pests, flying insect pests can be particularly troublesome. Such pests have been vectors for pathogenic organisms that can cause a variety of diseases in man and in domestic animals. Control of household flying insects for aesthetic, public health, and economic reasons are practiced all over the globe in human environments including houses, restaurants, food processing units, office buildings, and other locations in which humans or organic materials present an attractive environment for flying insect pests.
In the past, a number of pesticides have been identified that kill insect pests. Because of the toxicity of these chemicals to humans and to organisms other than those targeted by the pesticide, alternatives to routine pesticide use have been sought. Chemical attractants for pests are chemicals that can attract pests during a search for food, for oviposition (egg-laying) sites, or for mates. Many of these chemicals can be used as attractants to draw insect pests into mechanical traps or into poisoned baits for population control, for measurement of population densities and, for example, for selective or timed spray applications of the collected populations. In this way, insect attractants can be used for insect population control without pesticide or only with limited judicious pesticidal applications.
The science of insect pest attraction has a long history of development. The testing of attractants for attractancy has been performed in a variety of different ways. The testing methodology is rarely comparable. Further, published data on a chemical can be often contradictory. The earliest types of attractants were natural products related to hydrolyzed or decomposed protein materials or fermented plant materials. Natural attractants based on fermenting or decomposing natural products provide little opportunity to control release rates. Further, indoor use and outdoor use is severely limited by unacceptable odors and by rapid dehydration of the organic matter.
Attractants are typically relatively volatile organic compounds that can be released into the atmosphere. Each chemical attractant composition has a threshold level of attractancy at which point insects can detect the presence of the concentration of the attractant by olfactory receptors. Below such a threshold level, the chemicals tend not to be measurably different from nonattractive compositions in affecting insect behavior. Each attractant has an effective concentration range which is dependent upon its release rate into the environment within which the attractants are effective to alter the behavior of insects in a way that attracts the insects to the attractant composition. Above the effective concentration range for each attractant, the attractancy of the composition is typically lessened, and often at higher release rates, the resulting concentrations of the material in the atmosphere act as effective repellents. A few chemical attractants have been introduced for commercial use. These attractants are typically phermones which are chemicals released by insects for the purpose of attracting mates. Such compounds are used at very low levels and are typically dispensed into the environment on a carrier such as porous plastic or a natural product such as corncob grits.
A substantial need exists for an attractant material to be used in the human environment to attract insects, particularly flying insect pests, which is effective, is non-offensive to humans, and is nontoxic when used correctly.